FARNBOROUGH, England—Airbus Group SE’s jetliner boss Fabrice Brégier Wednesday said the European plane maker will have to secure a further 250 to 300 orders after this week to meet its full-year target.

Mr. Brégier told investors at the Farnborough air show, the biennial aerospace extravaganza southwest of London, that the plane maker should end the weeklong industry gathering with about 400 orders under its belt. The company earlier...